This invention relates generally to air conditioning systems and, more particularly, to an air conditioning system which is integrated into the internal structure of a bus.
The conventional integrated bus air conditioning systems contain a condenser mounted in a luggage compartment and an evaporator mounted in the luggage compartment or in a separate compartment between the passenger compartment floor and the luggage compartment underneath the floor. The evaporator takes in the return air through a central return air duct mounted under the floor of the passenger compartment and blows the conditioned supply air into a side wall supply air duct. The condenser, which, is interconnected to the evaporator by a refrigerant tube, operates to condense the refrigerant in the circuit by way of the outside air that is brought in from and eventually discharged to the ambient air.
As part of the refrigeration circuit which is fluidly interconnected by tubing to both the evaporator and the condenser, an open drive reciprocating compressor is generally directly driven by a belt drive from the bus engine, such that the speed of the compressor is dependent on the speed of the drive engine. Accordingly, when the bus is at idle speed, for example, the capacity of the air conditioning system is substantially reduced. Further, the refrigeration connections between the compressor and the air conditioning system is generally expensive to install, difficult to service, and somewhat unreliable because of possible refrigeration leaks and the need to maintain a compressor shaft seal.
Also typical of such a bus air conditioning system is the use of existing DC power to power the evaporator and condenser blower motors. Because of relatively low brush life for such motors, reliability and expense can also be a problem.
It is therefore an object of the present invention to provide an improved integrated air conditioning system for a bus.
Another object of the present invention is the provision for an integrated air conditioning system that does not occupy a significant portion of a luggage compartment on a bus.
Yet another object of the present invention is the provision in a bus for an air conditioning system whose performance is not significantly affected by the engine speed of a bus.
Yet another object of the present invention is an integrated bus air conditioning system which is economical to install and reliable in use.
Yet another object of the present invention is an integrated bus air conditioning system that is accessible and easy to service.
Still another object of the present invention is an integrated air conditioning system for a bus which is economical to manufacture and effective in use.
These objects and other features and advantages become more readily apparent upon reference to the following descriptions when taken in conjunction with the appended drawings.